In the field of fluid handling, valves are often used for the purpose of filling containers, such as bottles, on a manufacturing line. Containers on an assembly line are moved into position below valve assemblies and liquid flows through the valve assemblies and is dispensed into the containers. The valve assemblies are opened to allow liquid to enter the containers and then closed after the containers are appropriately filled. This fluid entering the valve assemblies is often under pressure. When a valve assembly is opened and closed under unrestrained flow conditions, the fluid exiting through the valve assembly has a tendency to splatter.
The problem of splattering is more likely when an aseptic type of valve assembly is used because aseptic valves typically include a diaphragm to seal the product/actuator stem interface. An aseptic valve assembly is typically used where sterile conditions are required, such as, inter alia, when food is being handled. For instance, when juice is being bottled, the juice is first heated and then cooled to insure that the juice is sterile. In addition, the bottle is sterilized prior to being filled. The juice travels through the valve assembly and is dispensed into the sterilized bottle. Aseptic valves, utilized for this purpose, typically include a diaphragm to seal the product/actuator stem interface in order to prevent the juice from exiting the valve at an undesirable location and to prevent contaminants from entering the juice through the valve assembly.
The use of a diaphragm in aseptic valves tends to result in a greater likelihood and occurrence of splattering. As the aseptic valve is opened or closed under unrestrained flow conditions, the diaphragm inside of the valve assembly has a tendency to flex, which exerts a pressure wave on the tip of the valve near the exit point of the valve assembly. The pressure wave typically occurs just as the tip of the valve approaches its seat, or point of closure, which causes a rapid acceleration of the liquid stream. Rapid acceleration can cause a disruption in the column of liquid exiting the valve assembly, such as a jetting effect, which causes the product to splash out of the container. This is an undesirable characteristic in that it results in a waste of the product as well as contamination or soiling of the production line. Thus, it is desirable to reduce the likelihood of splatter.
It is also desirable to provide a valve assembly which is useful with different types of products, including those having a tendency to foam. Foaming may be reduced by reducing or restricting the liquid filling velocity of the valve assembly. Thus, it is desirable to provide a valve assembly which is adjustable to provide varying rates of flow of the product through the valve assembly.